Facebook has announced that it is adding facial recognition software to help members tag photos in the U.S. The world's largest social network can help you to see your friends more easily, and they'll be able to use the software to see you.

"When you or a friend upload new photos, we use face recognition software -- similar to that found in many photo editing tools -- to match your new photos to other photos you're tagged in. We group similar photos together and, whenever possible, suggest the name of the friend in the photos," said Justin Mitchell, a Facebook engineer, in a post on the official Facebook blog. The company also said users could disable the feature for themselves, but friends would still be able to tag those users manually.

The facial recognition feature will roll out in the U.S. over the next few weeks, and so far, the comments section for the Mitchell blog post contains very few responses from people with privacy concerns. Most users wanted more details about how the service will work or how the tagging system might be turned off. Comments are hardly a scientific way to measure reaction, but they indicated no surge in concern about how facial recognition might be used as a tool by non-friends to identify people.

But despite the apparent lack of concern from members so far, the effects on privacy could be far reaching if this software is abused. Mitchell noted in the blog that "Every day, people add more than 100 million tags to photos on Facebook." That is a huge database of activity to monitor. An article in PC World suggested possible areas of concern:

But could Facebook ever identify people you're not friends with and suggest that you become friends with them? "Absolutely, it would be easy to do. All that data would be on that server farm. Technically, it's totally possible to expand that,' says Applied Recognition's Ganong.

As with most other software that is highly useful but can be manipulated by clever programmers, only time will tell whether facial recognition, a convenient feature, will turn out to be any danger to Facebook users.